//求1+2+3+...+n，要求不能使用乘除法、for、while、if、else、switch、case等关键字及条件判断语句（A?B:C）
class sum
{
public:
    sum()
    {
        _ret += _i;
        _i++;
    }
    static int getret()
    {
        return _ret;
    }
private:
    static int _i;
    static int _ret;
};

int sum::_i = 1;
int sum::_ret = 0;

class Solution {
public:
    int Sum_Solution(int n) 
    {
        sum* a = new sum[n];
        return sum::getret();
    }
};